The present invention relates to novel polyol-glycoside compositions for topical use.
The invention is of use preferably in the cosmetics field, but also in the dermopharmaceutical or pharmaceutical field, in the field of the textile industry, for example for treating woven or knitted, synthetic or natural textile fibers, or else in the field of the papermaking industry, for example for manufacturing paper for sanitary or domestic use.
The expression “for topical use” used in the context of the present description is therefore understood, in its widest sense, to denote any direct applications (in the case of a cosmetic, dermopharmaceutical or pharmaceutical product) or indirect applications (in the case of textile fibers or of paper) of a composition to the skin or the mucous membranes.
In its direct applications to the skin, the invention is directed more specifically toward compositions for improving the integrity of the skin by providing skin comfort.
The expression composition or substance capable of improving the “integrity of the skin” denotes any composition or substance having moisturizing properties resulting in particular from an ability to reinforce the epidermal moisture content by promoting in particular the synthesis of glycosaminoglycans and/or restructuring properties resulting in particular from an ability to increase the cellular cohesion of the skin by stimulating the synthesis of epidermal ceramides.
It is known that cosmetic compositions generally contain moisturizing substances, such as in particular polyols, ethoxylated polyols or hydrolyzed proteins.
Among the polyols, it is glycerol (polyol comprising three hydroxyl groups) which exhibits the highest moisturizing capacity. However, it has been noted that, at high dose, this can cause certain irritations of the skin and of the mucous membranes in particularly sensitive individuals.
The search for novel moisturizing substances that are tolerated better than glycerol has in particular led to the use of some of its derivatives such as in particular its acetals resulting from condensation with a reducing sugar.
These derivatives which effectively exhibit better skin tolerance than glycerol are characterized, however, by a moisturizing capacity that is generally lower than said glycerol.
Among the glycerol acetals, the products of acetalization of glycerol and of glucose described in document EP 0 770 378 appeared, up until now, to provide the best compromise between moisturizing capacity and skin tolerance.
It has been discovered, unexpectedly, and this constitutes the basis of the present invention, that the glycosides obtained by acetalization of certain polyols containing at least 4, and preferably 4 or 5, hydroxyl functions exhibit better moisturizing properties than the products described in document EP 0 770 378, while at the same time having identical skin tolerance.
This discovery is all the more surprising for going against a preconceived idea, since those skilled in the art know that the moisturizing capacity of polyols decreases when the number of hydroxyl functions increases.
In addition, it has been observed, entirely surprisingly, that the abovementioned glycosides exhibit notable restructuring properties resulting in particular in a better ability to increase the cellular cohesion of the skin than glycerol.